Developmental disturbances of the Teeth


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Developmental disturbances of the Teeth

  2. 2. DevelopmentalDisturbances (1) Size (2) Number and Eruption (3) Shape/Form (4) Defects of Enamel and Dentin
  3. 3. Size Microdontia Macrodontia
  4. 4. Size Microdontia  (1) True Generalized Microdontia  (2) Relative Generalized Microdontia  (3) Focal or Localized Microdontia
  5. 5. (1) True Generalized Microdontia all teeth are smaller than normal occur in some cases of pituitary dawrfism exceedingly rare teeth are well formed
  6. 6. (2) Relative Generalized Microdontia normal or slightly smaller than normal teeth are present in jaws that are somewhat larger than normal
  7. 7. (3) Focal/Localized Microdontia common condition affects most often maxillary lateral incisior + 3rd molar these 2 teeth are most often congenitally missing
  8. 8. (3) Focal/Localized Microdontia common forms of localized microdontia is that which affects maxillary lateral incisior  peg lateral  instead of parallel or diverging mesial + distal surfaces
  9. 9. (3) Focal/Localized Microdontia  sides converge or taper together incisally  forms cone-shaped crown  root is frequently shorter than usual
  10. 10. Size Microdontia Macrodontia
  11. 11. Size Macrodontia  (1) True Generalized Macrodontia  (2) Relative Generalized Macrodontia  (3) Focal or Localized Macrodontia
  12. 12. (1) True Generalized Macrodontia all teeth are larger than normal associated with pituitary gigantism exceedingly rare
  13. 13. (2) Relative Generalized Macrodontia normal or slightly larger than normal teeth in small jaws  results in crowding of teeth  insufficient arch space
  14. 14. (3) Focal/Localized Macrodontia uncommon condition unknown etiology usually seen with mandibular 3rd molars
  15. 15. DevelopmentalDisturbances (1) Size (2) Number and Eruption (3) Shape/Form (4) Defects of Enamel and Dentin
  16. 16. Number and Eruption Supernumerary Anodontia Impaction
  17. 17. Number and Eruption Supernumerary  results from continued proliferation of permanent or primary dental lamina to form third tooth germ  teeth may have: • normal morphology • rudimentary • miniature
  18. 18. Number and Eruption Supernumerary  more often in permanent dentition than primary dentition  more in the maxilla than in mandible
  19. 19. Number and Eruption Supernumerary  may be impacted erupted or impacted  because of additional tooth bulk, it causes: • malposition of adjacent teeth • prevent their eruption
  20. 20. Number and Eruption Supernumerary  many are impacted • characteristically found in cleidocranial dysostosis
  21. 21. Number and Eruption Supernumerary  Mesiodens  Fourth molar •Maxillary Paramolar • Distomolar or Distodens  Mandibular Premolar  Maxillary lateral incisors
  22. 22. Number and Eruption Supernumerary  Mandibular central incisors  Maxillary Premolars
  23. 23. Mesiodens most common supernumerary tooth tooth situated between maxillary central incisors  singly  paired  erupted or impacted 
  24. 24. Mesiodens small tooth cone-shaped crown short root
  25. 25. Fourth Molar 2nd most common situated distal to 3rd molar small rudimentary tooth, but may be of normal size mandibular 4th molar also is seen occasionally, but less common than maxillary molar
  26. 26. Paramolar small + rudimentary situated bucally or lingually to one of the maxillary molars interproximally between 1st + 2nd or 2nd + 3rd maxillary molars
  27. 27. Distomolar/Distodens molar located distal to molar
  28. 28. Number and Eruption Supernumerary Anodontia Impaction
  29. 29. Number and Eruption Anodontia  lack of tooth development  absence of teeth
  30. 30. Number and Eruption Anodontia  Complete Anodontia  Partial Anodontia • Hypodontia • Oligodontia  Pseudoanodontia  False Anodontia
  31. 31. Complete Anodontia when all teeth are missing rare often associated with a syndrome known as hereditary ectodermal dysplasia
  32. 32. Hypodontia lack of development of one or more teeth
  33. 33. Oligodontia lack of development of six or more teeth
  34. 34. Pseudoanodontia when teeth are absent clinically because of impaction or delayed eruption
  35. 35. False Anodontia when teeth have been exfoliated or extracted
  36. 36. Number and Eruption Supernumerary Anodontia Impaction
  37. 37. Number and Eruption Impaction  most often affects the mandibular 3rd molars + maxillary canines  less commonly: • premolars • mandibular canines • second molars
  38. 38. Number and Eruption Impaction  occurs due to obstruction from crowding  from some other physical barrier  occasionally, may be due to an abnormal eruption path, presumably because of unusual orientation of
  39. 39. Number and Eruption Impaction  Ankylosis
  40. 40. Ankylosis fusion of a tooth to surrounding bone with focal loss of periodontal ligament, bone + cementum become inextricably mixed  cause fusion of tooth to alveolar bone
  41. 41. DevelopmentalDisturbances (1) Size (2) Number and Eruption (3) Shape/Form (4) Defects of Enamel and Dentin
  42. 42. Shape and Form Crown Root
  43. 43. Shape and Form Crown  Fusion  Gemination  Taurodontism  Talon’s Cusp  Leong’s Cusp
  44. 44. Shape and Form Crown  Dens Invaginatus  Peg-shaped Lateral  Hutchinson Incisor  Mulberry Molar
  45. 45. Shape and Form Root  Concresence  Enamel Pearl  Dilaceration  Flexion  Ankylosis
  46. 46. Fusion joining of 2 developing tooth germs resulting in a single large tooth structure may involve entire length of teeth or may involve roots only, in which case cementum + dentin are SHARED
  47. 47. Fusion
  48. 48. Gemination fusion of 2 teeth from a single enamel organ partial cleavage appearance of 2 crowns that share same root canal trauma has been suggested as possible cause, the cause is still unknown
  49. 49. Taurodontism variation in tooth form:  elongated crowns  apically displaced furcations • resulting in pulp chambers that have apical occlusal height
  50. 50. Taurodontism may bee seen as isolated incident in families associated with syndromes such as  Down syndrome  Klinefelter’s syndrome
  51. 51. Taurodontism little clinical significance No treatment is required
  52. 52. Dens Evaginatus  Talon’s Cusp  Leung’s Premolar
  53. 53. Talon’s Cusp well-delineated additional cusp located on the surface of an anterior tooth extends at least half the distance from CEJ to incisal edge
  54. 54. Leung’s Cusp developmental condition clinically as an accessory cusp or a globule located on occlusal surface between buccal + lingual cusps of premolars unilaterally or bilaterally
  55. 55. Dens Invaginatus(Dens in Dente) deep surface invagination of crown or root that is lined by enamel 2 forms:  coronal  radicular
  56. 56. Dens Invaginatus(Dens in Dente) depth varies from slight enlargement of cingulum to a deep infolding that extends to apex historically, it has been classified into 3 major types:  Type I  Type II  Type III
  57. 57. Dens Invaginatus(Dens in Dente)  Type I • confined to the crown  Type II • extends below cemento enamel junction • ends in a blind sac • may or may not communicate with adjacent dental pulp
  58. 58. Dens Invaginatus(Dens in Dente)  Type III • extends through the root • perforates in the apical or lateral radicular area without any immediate communication with pulp
  59. 59. Peg-ShapedLateral undersized lateral incisor smaller than normal occurs when permanent lateral incisors do not fully develop
  60. 60. Peg-ShapedLateral
  61. 61. Hutchinson’s Incisor characteristic of congenital syphilis lateral incisors are peg-shaped or screwdriver-shaped widely spaced notched at the end with a crescent-shaped deformity
  62. 62. Hutchinson’s Incisor notches on their biting surfaces named after Sir Jonathan Hutchinson  English surgeon + pathologist who 1st described it
  63. 63. Mulberry Molar dental condition usually associated with congenital syphilis characterized by multiple rounded rudimentary enamel cusps on permanent 1st molars
  64. 64. Mulberry Molar dwarfed molars with cusps covered with globular enamel growths giving the appearance of a mulberry
  65. 65. Shape and Form Root  Concresence  Enamel Pearl  Dilaceration  Flexion  Ankylosis
  66. 66. Concrescence 2 fully formed teeth joined along the root surfaces by cementum noted more frequently in posterior and maxillary regions
  67. 67. Concrescence often involves a 2nd molar tooth in which its roots closely approximate the adjacent impacted 3rd molar may occur before or after the teeth have erupted usually involves only 2 teeth
  68. 68. Concrescence diagnosis can frequently be established by roentgenographic examination often requires no therapy unless union interferes with eruption; then surgical removal may be warrantedsince with fused teeth, extraction of one may result in extraction of the other
  69. 69. Enamel Pearls droplets of ectopic enamel or so called enamel pearls may occasionally be found on roots of teeth uncommon, minorabnormalities, which are formed on normal teeth
  70. 70. Enamel Pearls occur most commonly in bifurcation or trifurcation of teeth may occur on single-rooted premolar as well maxillary molars are commonly affected than mandibular molars
  71. 71. Enamel Pearls consist of only a nodule of enamel attached to dentin may have a core of dentin containing pulp horn may be detected on radiographic examination
  72. 72. Enamel Pearls may cause stagnation at gingival margin but, if they contain pulp, this will be exposed when pearl is removed
  73. 73. Dilaceration angulation or a sharp bend or curve in root or crown of a formed tooth trauma to a developing tooth can cause root to form at an angle to normal axis of tooth rare deformity
  74. 74. Dilaceration movement of crown or of the crown and part of root from remaining developing root may result in sharp angulation after tooth completes development
  75. 75. Dilaceration hereditary factors are believed to be involved in small number of cases eruption generally continues without problems
  76. 76. Flexion deviation or bend restricted just to the root portion usually bend is less than 90 degrees may be a result of trauma to the developing tooth
  77. 77. Ankylosis also known as “submerged teeth” fusion of a tooth to surrounding bone deciduous teeth most commonly mandibular 2nd molars  undergone variable degree of root resorption
  78. 78. Ankylosis  have become ankylosed to bone  this process prevents their exfoliation + subsequent replacement by permanent teeth  after adjacent permanent teeth have erupted, ankylosed tooth appears to have submerged below level of occlusion
  79. 79. DevelopmentalDisturbances (1) Size (2) Number and Eruption (3) Shape/Form (4) Defects of Enamel and Dentin
  80. 80. AmelogenesisImperfecta also known as:  Hereditary Enamel Dysplasia  Hereditary Brown Enamel  Hereditary Brow Opalescent Teeth
  81. 81. AmelogenesisImperfecta group of conditions caused by defects in the genes encoding enamel matrix proteins genes that encode for enamel proteins:  amelogenin mutated in  enamelin in patients  others with this condition
  82. 82. AmelogenesisImperfecta affects both dentition  deciduous  permanent classified based on pattern of inheritance:  hypoplasia  hypomaturation  hypocalcified
  83. 83. AmelogenesisImperfecta No treatment except for improvement of cosmetic appearance
  84. 84. HypoplasticAmelogenesis Imperfecta inadequate formation of matrix enamel is randomly:  pitted  grooved or very thin  hard + translucent defects become stained but teeth are not especially susceptible to caries unless enamel is scanty and easily damaged
  85. 85. HypoplasticAmelogenesis Imperfecta reduced enamel thickness  abnormal contour  absent interproximal contact points Radiographically:  enamel reduced in bulk  shows thin layer over occlusal + interproximal surfaces
  86. 86. HypoplasticAmelogenesis Imperfecta dentin + pulp chambers appear normal no treatment is necessary
  87. 87. HypomaturationAmelogenesis Imperfecta enamel is normal in form on eruption but:  opaque  white to brownish-yellow  softer than normal  tends to chip from underlying dentin
  88. 88. HypomaturationAmelogenesis Imperfecta Radiographically:  affected enamel exhibits radiodensity similar to dentin
  89. 89. HypocalcifiedAmelogenesis Imperfecta enamel matrix is formed in normal quantity poorly calcified when newly erupted:  enamel is normal in thickness  normal form  but weak  opaque or chalky in appearance
  90. 90. HypocalcifiedAmelogenesis Imperfecta with years of function:  coronal enamel is removed  except for cervical portion that is occasionally calcified better Radiographically:  density of enamel + dentin are similar
  91. 91. Dentinogenesis Imperfecta also known as “Hereditary Opalascent Dentin”  due to clinical discoloration of teeth mutation in the dentin sialophosphoprotein affects both primary + permanent dentition
  92. 92. Dentinogenesis Imperfecta have blue to brown discoloration with distinctive translucence enamel frequently separates easily from underlying defective dentin
  93. 93. Dentinogenesis Imperfecta Radiographically:  bulbous crowns  cervical constriction  thin roots  early obliteration of roots canals + pulp chambers
  94. 94. Dentinogenesis Imperfecta Treatment:  prevent loss of enamel + subsequent loss of dentin through attrition  cast metal crowns on posterior  jacket crowns on anterior teeth
  95. 95. Dentinogenesis Imperfecta Classification:  Type I  Type II  Type III
  96. 96. Type I DentinogenesisImperfecta occurs in families with Osteogenesis Imperfecta primary teeth are more severely affected than permanent teeth
  97. 97. Type I DentinogenesisImperfecta Radiographically:  partial or total obliteration of pulp chambers + root canals  by continued formation of dentin  roots may be short + blunted  cementum, periodontal membrane + bone appear normal
  98. 98. Type II DentinogenesisImperfecta never occurs in association with osteogenesis imperfecta unless by chance most frequently referred to as hereditary opalascent dentin only have dentin abnormalities and no bone disease
  99. 99. Type II DentinogenesisImperfecta Radiographically:  partial or total obliteration of pulp chambers + root canals  by continued formation of dentin  roots may be short + blunted  cementum, periodontal membrane + bone appear normal
  100. 100. Type III DentinogenesisImperfecta “Bradwine type” racial isolate in Maryland multiple pulp exposures in deciduous not seen in type I or II periapical radiolucencies
  101. 101. Type III DentinogenesisImperfecta enamel appears normal large size of pulp chamber is due not to resorption but rather to insufficient + defective dentin formation
  102. 102. Dentin Dysplasia also known as “Rootless Teeth” rare disturbance of dentin formation normal enamel atypical dentin formation abnormal pulpal morphology hereditary disease
  103. 103. Dentin Dysplasia Classification:  Type I (Radicular Type)  Type II (Coronal Type)
  104. 104. Type I (Radicular Type) both dentitions are of normal color periapical lesion premature tooth loss may occur because of short roots or periapical inflammatory lesions
  105. 105. Type I (Radicular Type) Radiographically:  roots are extremely short  pulps almost completely obliterated  periapical radiolucencies: • granulomas • cysts • chronic abscesses
  106. 106. Type II (Coronal Type) color of primary dentition is opalescent permanent dentition is normal coronal pulps are usually large (thistle tube appearance)  filled with globules of abnormal dentin
  107. 107. Type II (Coronal Type) Radiographically: (Deciduous)  roots are extremely short  pulps almost completely obliterated (Permanent)  abnormally large pulp chambers in coronal portion of tooth
  108. 108. RegionalOdontodysplasia also known as:  Odontogenic Dysplasia  Odontogenesis Imperfecta  Ghost Teeth
  109. 109. RegionalOdontodysplasia one or several teeth in a localized area are affected maxillary teeth are involved more frequently than mandibular area etiology is unknown
  110. 110. RegionalOdontodysplasia teeth affected may exhibit a delay or total failure in eruption shape is altered, irregular in appearance
  111. 111. RegionalOdontodysplasia Radiographically:  marked reduction in radiodensity  teeth assume a “ghost” appearance  both enamel + dentin appear very thin  pulp chamber is exceedingly large
  112. 112. RegionalOdontodysplasia Treatment:  poor cosmetic appearance of teeth  extraction with restoration by prosthetic appliance
  113. 113. Shell Tooth normal thickness enamel extremely thin dentin enlarged pulps thin dentin may involve entire tooth or be isolated to the root most frequently in deciduous
  114. 114. References: Books  Cawson, R.A: Cawson’s Essentials of Oral Oral Pathology and Oral Medicine, 8th Edition • (pages 24-36)  Neville, et al: Oral and Maxillofacial Pathology 3rd Edition • (pages 77-113)  Regezi, Joseph et al: Oral Pathology, Clinical Pathological Correlations 5th Edition • (pages 361-373)  Shafer, et al: A textbook of Oral Pathology, 3rd Edition • (pages 37-69)